In the weaving art, particularly for the weaving of glass fibers, and like textile materials, hot wire cutters are utilized to trim the selvage edges of the fabric being produced. The cutters are typically supplied with low voltage and high current, and there is a tendency for the cutters to burn out from the intense heat at which they operate. When a cutter wire burns out there is no immediately apparent indication that such an event has occurred, and the loom continues to weave fabric, but with a rough selvage. Since each operator typically has a number of looms that he/she is responsible for (typically 50-200 looms), a given loom may continue to weave for a long period of time before the burned out cutter wire is detected, resulting in the production of fabric with unacceptable selvage.
According to the present invention, a structure, and method, are provided to ensure that unacceptable selvage fabric--as a result of cutter wire burnout--will not be produced. According to the invention, the loom is automatically stopped whenever a cutter wire burns out, or is otherwise disabled.
In the preferred embodiment of the invention, a minimum number of components are utilized in order to effect loom stoppage as a result of cutter wire failure. A conventional loom typically includes a plurality of drop wires, each of which is associated with a warp end on the loom. The drop wires detect warp end breakage, and are conventionally connected to a knock-off solenoid which effects loom stoppage upon warp end breakage. According to the preferred embodiment of the invention, a few simple electrical components are interconnected between the cutter wire circuitry and the drop wire circuitry, so that the same loom-stoppage mechanism stops loom operation as a result of either cutter wire failure or warp end breakage--yet the operator can readily distinguish which of the two events has caused the loom stoppage.
The preferred embodiment of the invention includes a coil which is connected in series with the hot wire cutters, and which has a hollow core. A conventional reed switch, which has the contacts thereof normally biased to a closed position (but which open under the influence of the coil) is inserted into the core of the coil, and the reed switch and an indicator light (or like indicating means) are connected in parallel with the drop wires. When a cutter wire fails, the coil is deenergized, the reed switch contacts close, the indicator light goes on, and the knock-off solenoid stops operation of the loom. By inspecting the light the operator readily can determine that loom stoppage was a result of cutter wire failure, and then proceed to correct the problem. If the loom stops and the indicator light is not lit, then the operator knows that loom stoppage was the result of warp end breakage.
It is the primary object of the present invention to provide for the simple and effective stoppage of a loom (or other device) as a result of hot wire cutter failure. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.